Water drain reservoir

ABSTRACT

The invention relates to a water drain reservoir comprising a coherent man-made vitreous fibre substrate (MMVF substrate) and a conduit having two open ends, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition, wherein a first open end of the conduit is in fluid communication with the MMVF substrate.

The present invention relates to a water drain reservoir, the use of a water drain reservoir, and a method of dissipating surface water.

Precipitation such as rain, snow, sleet, hail and the like results in surface water which needs to be disposed of. Buildings commonly have guttering which collects precipitation which has fallen on a roof. The guttering is connected to a drainpipe and the resulting water can be disposed of via mains drainage.

Increasingly, it is desirable for the surface water to be disposed of without the use of mains drainage. One option is that the water can be harvested in a rain water butt which can then be used for watering a garden.

EP1818463 discloses a different solution of a water drain tank or channel module made of a plastic box with open lattice walls covered by a water-permeable geo-textile material. This water drain tank or channel module is surrounded by sediment and releases the water from the box in a controlled way. The geo-textile material is required to prevent sediment from entering the tank or module.

DE2155594 discloses a water drain reservoir made of open-pored foam, such as polyurethane. It is difficult to make a foam with a 100% open foam structure. The lower the degree of open-pores, the less water a foam structure can hold. The less water the foam structure holds, the larger it needs to be to hold a given amount of water. The reduced water holding capacity of a foam substrate means that it is only able to buffer a low level of water. A disadvantage of foam water drain reservoirs is that if the ground water level is high, the foam water drain reservoir can float in the water, and thus rise out of the ground.

There is a need for a device that can store surface water and gradually dissipate this to the ground. Further, there is a need for a device that does not become contaminated with sediment from the ground. Further, there is a need for a device that can be installed without being wrapped in a geo-textile material. Further, there is a need to improve the storage capability of the device so that a device stores more water per volume. Further there is a need for a device which remains in the ground when the ground water level rises. Further there is a need to increase the buffering capacity of such a device, that is the difference between the maximum amount of water that can be held, and the amount of water that is retained when the device gives off water. It is also desirable to provide such a device which is environmentally acceptable and economical in terms of its production. The present invention solves the above detailed problems.

SUMMARY OF INVENTION

In a first aspect of the invention, there is provided a water drain reservoir comprising a coherent man-made vitreous fibre substrate (MMVF substrate) and a conduit having two open ends, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition, wherein a first open end of the conduit is in fluid communication with the MMVF substrate.

In a second aspect of the invention, there is provided use of a water drain reservoir comprising a coherent MMVF substrate and a conduit with two open ends, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition, wherein a first open end of the conduit is in fluid communication with the MMVF substrate, as a water dissipating system wherein the water drain reservoir is positioned in the ground, whereby water flows along the conduit and is absorbed by the MMVF substrate, wherein the water is dissipated by the MMVF substrate into the ground.

In a third aspect of the invention, there is provided a method of dissipating surface water comprising providing a water drain reservoir comprising a coherent MMVF substrate and a conduit with two open ends, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition, wherein a first open end of the conduit is in fluid communication with the MMVF substrate, positioning the MMVF substrate in the ground wherein surface water flows along the conduit and is absorbed by the MMVF substrate and wherein the water dissipates from the MMVF substrate into the ground.

DETAILED DESCRIPTION OF THE INVENTION

MMVF substrates are known for numerous purposes, including for sound and thermal insulation, fire protection and in the field of growing plants. When used for growing plants, the MMVF substrate absorbs water to allow plants to grow. When used for growing plants, it is important that the MMVF substrate does not dry out. In the field of growing plants, an MMVF substrate is normally used instead of soil to grow plants. The relative capillarity of soil and an MMVF substrate is not important in the field of growing plants. WO01/23681 discloses the use of MMVF substrate as a sewage filter.

The present invention provides the use of a coherent MMVF substrate as a water drain reservoir. The man-made vitreous fibres are bonded with a cured binder composition and the water drain reservoir can retain water within its open pore structure.

In use, the MMVF substrate is positioned in the ground and is preferably buried within the ground. Preferably the MMVF substrate is completely covered with earth. Earth includes sediment, sand, clay, dirt, gravel and the like. For example, the MMVF substrate may be buried under at least 20 cm of earth, preferably at least 40 cm of earth, most preferably at least 50 cm of earth.

The conduit may be an open channel, and water may flow along this channel into the MMVF substrate. Preferably the conduit is a pipe. An advantage of a pipe is that it is hollow and can therefore freely transport water underground to a MMVF substrate. Further, the wall of the pipe prevents debris from entering the pipe.

Preferably the conduit, preferably a pipe, is positioned in fluid communication with the top section of the MMVF substrate. This means that on installation, the conduit is positioned in fluid communication with the top half of the MMVF substrate by volume. The conduit may be in fluid communication with the top surface of the MMVF substrate. The conduit is preferably in fluid communication with the top part of a side wall of the MMVF substrate. An advantage of the conduit being positioned in fluid communication with the top section of the MMVF is that in order to install the device, the conduit, preferably a pipe can be installed at a depth of the top of the device, rather than at a depth of the bottom of the device. This means that less effort is required to install the device. The conduit, preferably a pipe, is in fluid communication with the MMVF, and may be in fluid communication with a system of conduits, preferably pipes and one or more drainpipes so that water which flows off a roof, into a gutter, down a drainpipe can be stored within MMVF substrate during wet weather. As the surrounding ground dries out, the water gradually dissipates from the MMVF substrate into the ground. The water drain reservoir thus provides an effective way to dispose of rain water which does not put any pressure on existing sewage systems. It is not necessary to transport the water elsewhere; the water is disposed of within the ground and preferably within the grounds of the building. It is envisaged that each property may have one, or several, water drain reservoirs connected to their guttering systems, and thus each property is able to dispose of this surface water within their own grounds.

Alternatively, several properties may use the same water drain reservoir for disposal of surface water. There may be more than one source of the water which is dissipated by the water drain reservoir. There may be a network of conduits, preferably pipes, which lead to the water drain reservoir.

Preferably, the water drain reservoir is provided with a conduit, preferably a pipe, partially embedded into a MMVF substrate. This ensures that water can flow along the conduit, and directly into the MMVF substrate. The MMVF is in fluid communication with the conduit. It is, of course envisaged that the MMVF substrate can butt up against the conduit, preferably a pipe, through which rain water will flow, in order to achieve this fluid communication. It is preferable however for efficiency for the conduit to be at least partially embedded into the MMVF substrate. The embedded part of the conduit may have an aperture in its outer wall, preferably more than one aperture. The presence of an aperture has the advantage of there being a greater area through which the water can flow into the MMVF substrate.

The MMVF substrate may have a passage which extends from a first end of the MMVF substrate, towards a second end of the MMVF substrate, wherein the first and second ends are opposed and wherein the first end of the passage is in fluid communication with water from the conduit, preferably a pipe. The passage may extend 10% to 100% of the way through the MMVF substrate, preferably 20% to 99% of the way through the MMVF substrate, preferably 50% to 99% of the way through the MMVF substrate, more preferably 80% to 95% of the way through the substrate. The advantage of the passage is that there is a greater area through which the water can flow into the MMVF substrate. The passage may have any cross-sectional shape, preferably circular, triangular or square.

The passage may be formed by embedding the conduit, preferably a pipe into the MMVF substrate as described above. The conduit, preferably has an aperture in its outer wall, preferably more than one aperture. The presence of an aperture has the advantage of there being a greater area through which the water can flow into the MMVF substrate.

The passage may be formed by a separate pipe which has at least one aperture. The pipe is preferably a perforated plastic pipe, such as a PVC pipe. The pipe gives strength to the drain and prevents the passage from becoming closed. The pipe is perforated to allow the water to drain into the passage. The embedded pipe provides support to the passage to make it more resilient or resistant to pressure. In the absence of a pipe, the passage could become closed due to pressure on the MMVF substrate, such as vehicles moving over the MMVF substrate.

The passage may be formed by removing a section of the MMVF substrate, such as by drilling. The resulting passage will be porous and thus allow water to be absorbed into the MMVF substrate from the passage.

The MMVF substrate may comprise a first part in contact with a second part, wherein the passage is disposed between the first part and the second part. This means that the first part may be preformed with a groove along at least part of the length of the MMVF substrate, and when the first part and second parts are joined together, the passage is formed by the groove and the second part. Alternatively the second part may have the groove. Alternatively, both the first and second parts may have a groove and the grooves may be lined up to form the passage when the first and second parts are joined together. The groove or grooves may be of any shape as required to form the passage. The groove or grooves may therefore have a cross-section which is semicircular, triangular, rectangular or the like.

The first and second parts of the MMVF substrate may be joined by placing the two parts together, or using an adhesive.

The passage may be formed by a combination of the means described above.

Preferably the cross-sectional area of the first and second ends of the passage are in the range 2 to 200 cm², preferably 5 to 100 cm².

Preferably the cross-sectional area of the first end of the passage is 0.5% to 15% of the cross-sectional area of the first end of the MMVF substrate, preferably 1% to 10%.

Preferably the cross-sectional area of the second end of the passage is 0.5% to 15% of the cross-sectional area of the second end MMVF substrate, preferably 1% to 10%.

The openings are such a small percentage of the cross-sectional area of the ends of the MMVF substrate since the vast majority of the MMVF substrate is used to buffer the amount of water that is conveyed to the MMVF substrate. The larger the proportion of the MMVF substrate, the greater the volume of water that can be buffered by a MMVF substrate of a given cross-sectional area.

The cross-sectional area of the passage is preferably substantially continuous along its length. Substantially continuous means that the cross-sectional area is within 10% of the average cross-sectional area, preferably within 5%, most preferably within 1%. If necessary however, the cross-sectional area can be varied according to the requirements of the passage to be smaller or larger.

The passage is may be straight through the MMVF substrate, that is, the passage takes the most direct route towards the second end of the MMVF substrate to allow water to take the most direct route along the passage.

The passage may follow an indirect route through the MMVF substrate to increase the surface area of the passage so that water can drain into the MMVF substrate at a faster rate.

There may be more than one passage through the substrate to increase the surface area of the passage so that water can drain into the MMVF substrate at a faster rate. Where there is more than one passage, the passages are preferably connected to form a network of passages so that water may flow through the network of passages. Each passage may be in fluid communication with a different conduit thus allowing water from different sources to be disposed of by the water drain reservoir.

The passage may have a triangular cross-section. When installed, the base of the triangle is preferably parallel with the base of the MMVF substrate. Alternatively the passage can have a semicircular cross-section. Again, the base of the MMVF substrate is preferably parallel with the base of the semicircle. Alternatively, the passage can have a circular or a rectangular cross-section. The advantage of these passage cross-sections is that the largest surface area of the passage is at the lowest point which gives the largest surface area for the water to flow through.

The passage is preferably positioned centrally in the width of the cross-section of the MMVF substrate. The reason that this is substantially centrally, is so that the flow of the water which is to be absorbed will be down the centre of the MMVF substrate. This has the advantage that the strength of the MMVF substrate is maintained at the sides of the MMVF substrate. If however the passage was arranged close to one side of the MMVF substrate, this may cause a weakness in the structure.

Preferably the passage is offset towards a first direction. The advantage of this is that the MMVF substrate may be installed with the passage at the top of the water drain reservoir to allow the water to drain into the main body of the MMVF substrate

In use, when the passage extends from the first end to the second end of the MMVF substrate, the second end of the passage is preferably closed to prevent earth from entering the passage and reducing the size of the passage. The second end of the passage may be closed by arranging a plate over the opening, such as an MMVF plate, a metal plate, a plastic plate or the like. Alternatively, the second end of the passage may be plugged, such as with a plug made from MMVF, metal, plastic or the like. The second end may be wrapped in a geo-textile material to close the second end of the passage.

A water drain reservoir may be provided in kit form comprising a conduit and a coherent MMVF substrate, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition.

A series of MMVF substrates may be connected together to increase the volume of water that can be stored and then dissipated. These MMVF substrates may be placed next to each other so that water can dissipate from one MMVF substrate to the next. Alternatively, a conduit, preferably a pipe, with apertures can run through a first MMVF substrate, and then be at least partially embedded into a second MMVF substrate. The conduit may extend all the way through the second MMVF substrate as discussed above. This allows any water which is not absorbed by the first MMVF substrate to flow into the second MMVF substrate. There may also be more than two MMVF substrates connected in this way such as 3, 4, 5, or 6.

The man-made vitreous fibres (MMVF) can be glass fibres, ceramic fibres, basalt fibres, slag wool, stone wool and others, but are usually stone wool fibres. Stone wool generally has a content of iron oxide at least 3% and content of alkaline earth metals (calcium oxide and magnesium oxide) from 10 to 40%, along with the other usual oxide constituents of MMVF. These are silica; alumina; alkali metals (sodium oxide and potassium oxide) which are usually present in low amounts; and can also include titania and other minor oxides.

Fibre diameter is often in the range of 1 to 20 μm, preferably 3 to 5 μm.

The MMVF substrate is in the form of a coherent mass. That is, the MMVF substrate is generally a coherent matrix of MMVF fibres, which has been produced as such, but can also be formed by granulating a slab of MMVF and consolidating the granulated material.

Preferably the water holding capacity of the MMVF substrate is at least 80% of the volume, preferably 80-99%, most preferably 85-95%. The greater the water holding capacity, the more water that can be stored for a given volume. The water holding capacity of the MMVF substrate is high due to the open pore structure and the MMVF substrate being hydrophilic.

Preferably the amount of water that is retained by the MMVF substrate when it gives off water is less than 20% vol, preferably less than 10% vol, most preferably less than 5% vol. The water retained may be 2 to 20% vol, such as 5 to 10% vol. The lower the amount of water retained by the MMVF substrate, the greater the capacity of the MMVF substrate to take on more water. Water may leave the MMVF substrate by dissipating into the ground when the surrounding ground is dry and the capillary balance is such that the water dissipates into the ground.

Preferably the buffering capacity of the MMVF substrate, that is the difference between the maximum amount of water that can be held, and the amount of water that is retained when the MMVF substrate gives off water is at least 60% vol, preferably at least 70% vol, preferably at least 80% vol. The buffering capacity may be 60 to 90% vol, such as 60 to 85% vol. The advantage of such a high buffering capacity is that the MMVF substrate can buffer more water for a given volume, that is the MMVF substrate can store a high volume of water when it rains, and release a high volume of water as the surrounding ground dries out. The buffering capacity is so high because MMVF substrate requires a low suction pressure to remove water from the MMVF substrate. This is demonstrated in the Example.

The water holding capacity, the amount of water retained and the buffering capacity of the MMVF substrate can be measured in accordance with EN 13041-1999.

The water is stored in the MMVF substrate when the surrounding ground is saturated, that is the capillary balance means that the water is retained within the MMVF substrate. As the surrounding ground dries out, the capillary balance shifts, and the water dissipates from the MMVF substrate into the surrounding ground. In this way, water is held within the MMVF substrate when the surrounding ground is saturated. When the surrounding ground dries out, the water dissipates from the MMVF substrate into the ground. The MMVF substrate is then able to take on more water, when this flows down the conduit, preferably a pipe, into the MMVF substrate.

The structure of the MMVF substrate is such that whilst water can dissipate from the substrate into the ground, earth does not contaminate the MMVF substrate. This is due to the small pore size within the substrate. It is therefore not necessary to wrap the MMVF substrate in a geo-textile to prevent contamination. This has the advantage that on installation, the MMVF substrate does not have to be manually wrapped in a geo-textile material by the installer. The wrapping step of the known water drain reservoirs is awkward and time consuming, since it is performed at the installation stage. The water drain reservoir of this invention overcomes this problem.

The binder may be any of the binders known for use as binders for coherent MMVF products.

The MMVF substrate is hydrophilic, that is it attracts water. The MMVF substrate is hydrophilic due to the binder system used. In the binder system, the binder itself may be hydrophilic and/or a wetting agent used.

The hydrophilicity of a sample of MMVF substrate can be measured by determining the sinking time of a sample. A sample of MMVF substrate having dimensions of 100×100×65 mm is required for determining the sinking time. A container with a minimum size of 200×200×200 mm is filled with water. The sinking time is the time from when the sample first contacts the water surface to the time when the test specimen is completely submerged. The sample is placed in contact with the water in such a way that a cross-section of 100×100 mm first touches the water. The sample will then need to sink a distance of just over 65 mm in order to be completely submerged. The faster the sample sinks, the more hydrophilic the sample is. The MMVF substrate is considered hydrophilic if the sinking time is less than 120 s. Preferably the sinking time is less than 60 s. In practice, the MMVF substrate may have a sinking time of a few seconds, such as less than 10 seconds.

For instance, the binder, including any oil required may be hydrophobic, such as a phenol urea formaldehyde binder.

When the binder is hydrophobic, preferably a wetting agent is additionally included in the MMVF substrate. A wetting agent will increase the amount of water that the MMVF substrate can absorb. The wetting agent may be any of the wetting agents known for use in MMVF substrates that are used as growth substrates. For instance it may be a non-ionic wetting agent such as Triton X-100. Some non-ionic wetting agents may be washed out of the MMVF substrate over time. It is therefore preferable to use an ionic wetting agent, especially an anionic wetting agent, such as linear alkyl benzene sulphonate. These do not wash out of the MMVF substrate to the same extent.

EP1961291 discloses a method for producing water-absorbing fibre products by interconnecting fibres using a self-curing phenolic resin and under the action of a wetting agent, characterised in that a binder solution containing a self-curing phenolic resin and polyalcohol is used. This binder can be used in the present invention. Preferably, the wetting agent does not become washed out of the MMVF substrate and therefore does not contaminate the surrounding ground.

The binder of the MMVF substrate can be hydrophilic, that is it attracts water. The effect of using the hydrophilic cured binder in the MMVF substrate is that the MMVF substrate can absorb more water than when a hydrophobic binder is used. A hydrophilic binder does not require the use of a wetting agent. A wetting agent can be used to increase the hydrophilicity of either a hydrophobic or a hydrophilic binder. This means that the MMVF substrate will absorb a higher volume of water than if the wetting agent is not present. Any hydrophilic binder can be used.

The binder may be a formaldehyde-free aqueous binder composition comprising: a binder component (A) obtainable by reacting at least one alkanolamine with at least one carboxylic anhydride and, optionally, treating the reaction product with a base; and a binder component (B) which comprises at least one carbohydrate, as disclosed in WO2004/007615. This binder is hydrophilic.

WO 97/07664 discloses a hydrophilic substrate that obtained its hydrophilic properties from the use of a furan resin as a binder. The use of a furan resin allows the abandonment of the use of a wetting agent. This binder may be used in the present invention.

WO07129202 discloses a hydrophilic curable aqueous composition wherein said curable aqueous composition is formed in a process comprising combining the following components:

-   -   (a) a hydroxy-containing polymer,     -   (b) a multi-functional crosslinking agent which is at least one         selected from the group consisting of a polyacid, salt(s)         thereof and an anhydride, and     -   (c) a hydrophilic modifier;

wherein the ratio of (a):(b) is from 95:5 to about 35:65.

The hydrophilic modifier can be a sugar alcohol, monosaccharide, disaccharide or oligosaccharide. Examples given include glycerol, sorbitol, glucose, fructose, sucrose, maltose, lactose, glucose syrup and fructose syrup. This binder can be used in the present invention.

Further, a binder composition comprising:

-   -   a) a sugar component, and     -   b) a reaction product of a polycarboxylic acid component and an         alkanolamine component,

wherein the binder composition prior to curing contains at least 42% by weight of the sugar component based on the total weight (dry matter) of the binder components may be used in the present invention, preferably in combination with a wetting agent.

Binder levels are preferably in the range 0.5 to 5 wt %, preferably 2 to 4 wt % based on the weight of the MMVF substrate.

Levels of wetting agent are preferably in the range 0 to 1 wt %, based on the weight of the MMVF substrate, in particular in the range 0.2 to 0.8 wt %, especially in the range 0.4 to 0.6 wt %.

The MMVF product may be made in any of the ways known to those skilled in the art for production of MMVF growth substrate products. In general, a mineral charge is provided, which is melted in a furnace to form a mineral melt. The melt is then formed into fibres by means of centrifugal fiberisation e.g. using a spinning cup or a cascade spinner, to form a cloud of fibres. These fibres are then collected and consolidated. Binder and optionally wetting agent are usually added at the fiberisation stage by spraying into the cloud of forming fibres. These methods are well known in the art.

The MMVF substrate may have density in the range 60 to 200 kg/m³, in particular in the range 130 to 150 kg/m³. The advantage of this density is that the MMVF substrate has a relatively high compression strength. This is important as the MMVF substrate may be installed in a position where people or vehicles need to travel over the ground in which the MMVF substrate is positioned. Optionally a force distribution plate is positioned on top of the MMVF substrate in order to distribute the force applied to the MMVF substrate. Preferably such a force distribution plate is not required due to the density of the MMVF substrate.

The dimensions of a water drain reservoir may be in the range: height 0.3-1.2 m; width 0.15-0.8 m; and length 0.5-1.5 m. The volume of a water drain reservoir may be 0.025-1.4 m³, preferably 0.05-1 m³, preferably 0.1-0.5 m³. The typical dimensions of a water drain reservoir according to the invention are 0.6 m×0.2 m×1.0 m (height×width×length). This provides a water drain reservoir with a volume of 0.12 m³, which has proven satisfactory for use in relation to a typical single family house. The dimensions and thus the volume of a water drain reservoir may of course be varied depending on the actual use. A plurality of water drain reservoirs may also be combined to achieve the desired total volume as described earlier.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows schematically a water drain reservoir dug into the ground and connected to the guttering of a house, and

FIG. 2 shows water retention curves for a MMVF substrate, a foam substrate and silt loam.

DETAILED DESCRIPTION OF FIGURES

FIG. 1 shows a MMVF substrate 1 that has been dug into the ground 2 in the vicinity of a house 3. The house 3 is provided with gutters 4 that collect water from the roof 5 and lead it to the MMVF substrate 1 via a drain pipe 6 and a conduit 7. The conduit 7 is in fluid communication with the MMVF substrate 1. The conduit 7 may butt up against the MMVF substrate 1, but preferably it is partly embedded in the MMVF substrate 1 in order to ensure that debris is not entering the conduit 7. In the part that is embedded in the MMVF substrate 1 the conduit 7 may be provided with apertures 8 to increase the fluid communication area between the conduit 7 and the MMVF substrate 1.

The invention will now be described in the following example which does not limit the scope of the invention.

Example

The water holding capacity of a MMVF substrate, foam substrate and silt loam were tested in accordance with EN 13041-1999. The MMVF substrate was a stone wool fibre product with a phenol-urea formaldehyde (PUF) binder and a non-ionic surfactant wetting agent. The foam substrate was a polyurethane foam substrate. The results are shown in FIG. 2.

The MMVF substrate has a maximum water content of 90% vol. When the MMVF substrate gives off water, it retains about 2-5% vol of water. This means that the MMVF substrate has a buffering capacity of 85-87% vol. The foam substrate however has a maximum water content of 46-47% vol. When the foam substrate gives off water it retains about 27% vol of water. The buffering capacity of the foam is therefore only 19-20% vol. This shows that the MMVF substrate has a higher maximum water content than the foam substrate, as well as a lower water retention level. Therefore the MMVF substrate has a higher water buffering capacity than the foam substrate. The data shows that a foam substrate will need to be at least four times the volume of the MMVF substrate to buffer the same amount of water.

The maximum water content of the silt loam is similar to that of the foam substrate, and lower than the MMVF substrate. The capillarity of the silt loam is much higher than that of the MMVF substrate, which means you need a suction pressure of several meters to withdraw water from the silt loam. This means that the soil will easily drain water from the MMVF substrate as soon as the soil is not saturated.

It will be appreciated by the skilled person that any of the preferred features of the invention may be combined in order to produce a preferred method, product, binder composition or use of the invention. 

1. A water drain reservoir comprising a substrate and a conduit having two open ends, wherein a first open end of the conduit is in fluid communication with the substrate, characterised in that the substrate is a coherent man-made vitreous fibre substrate (MMVF substrate), wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition.
 2. A water drain reservoir according to claim 1, wherein the first open end of the conduit is at least partially embedded in the MMVF substrate.
 3. A water drain reservoir according to claim 1, wherein the conduit is a pipe.
 4. A water drain reservoir according to claim 1, wherein the water holding capacity of the MMVF substrate is at least 80% of the volume, preferably 80-99%, most preferably 85-95%.
 5. A water drain reservoir according to claim 1, wherein the buffering capacity of the MMVF is 60 to 90% vol.
 6. A water drain reservoir according to claim 1, wherein the MMVF substrate has a density in the range 60 to 200 kg/m³, preferably in the range 130 to 150 kg/m³.
 7. A water drain reservoir according to claim 1, wherein the MMVF substrate further comprises a wetting agent.
 8. Use of a water drain reservoir comprising a substrate and a conduit with two open ends, wherein a first open end of the conduit is in fluid communication with the substrate, as a water dissipating system wherein the water drain reservoir is positioned in the ground, whereby water flows along the conduit and is absorbed by the substrate, wherein the water is dissipated by the substrate into the ground, characterised in that the substrate is a MMVF substrate, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition.
 9. Use according to claim 8, wherein the conduit is positioned in fluid communication with the top section of the MMVF substrate.
 10. Use according to claim 8, wherein the first open end of the conduit is at least partially embedded in the MMVF substrate.
 11. A method of dissipating surface water comprising providing a water drain reservoir comprising a substrate and a conduit with two open ends, wherein a first open end of the conduit is in fluid communication with the substrate, positioning the substrate in the ground wherein surface water flows along the conduit and is absorbed by the substrate and wherein the water dissipates from the substrate into the ground, characterised in that the substrate is a MMVF substrate, wherein the MMVF substrate comprises man-made vitreous fibres bonded with a cured binder composition.
 12. A method according to claim 11, wherein the surface water is flowing into a drain pipe that is in fluid communication with a second open end of the conduit.
 13. A method according to claim 11, wherein the first open end of the conduit is at least partially embedded in the MMVF substrate.
 14. A method of claim 11, wherein the conduit is a pipe.
 15. A method according to claim 11, the water holding capacity of the MMVF substrate is at least 80% of the volume, preferably 80-99%, most preferably 85-95%.
 16. A method according to claim 11, wherein the buffering capacity of the MMVF is 60 to 90% vol.
 17. A method according to claim 11, wherein the MMVF substrate has a density in the range 60 to 200 kg/m³, preferably in the range 130 to 150 kg/m³.
 18. A method according to claim 11, wherein the MMVF substrate further comprises a wetting agent.
 19. Use according to claim 8 wherein the conduit is a pipe.
 20. Use according to claim 8, wherein the water holding capacity of the MMVF substrate is at least 80% of the volume, preferably 80-99%, most preferably 85-95%.
 21. Use according to claim 8, wherein the buffering capacity of the MMVF is 60 to 90% vol.
 22. Use according to claim 8, wherein the MMVF substrate has a density in the range 60 to 200 kg/m³, preferably in the range 130 to 150 kg/m³.
 23. Use according to claim 8, wherein the MMVF substrate further comprises a wetting agent. 